Patent GB-611612-A (GB)
Title: Improvements in or relating to the treatment of polysulphide polymers
IPC: C08L81/00
Filed: 1944-09-14
Abstract: Polysulphide polymers are treated with an alkaline mono- or hydrosulphide or hydrogen sulphide in the presence of an oxygen acceptor such as alkaline sulphites and pyrogallates.  The starting polymers may be linear or wholly or partly cross-linked, e.g. those made by reacting an alkaline polysulphide with organic compounds having two or three halogen atoms per molecule, or a mixture of such compounds, respectively.  Suitable halogen compounds include di-halogenated hydrocarbons, ethers, formals (e.g. dichlordiethyl formal) and glycols, and 1 : 2 : 3-trichloropropane.  The starting polymers may also be those obtained by oxidation of compounds containing a plurality of -SH groups.  The products may be mixed with fillers, e.g. ground cork, asbestos, cotton flock, wood flour, carbon black, zinc oxide; plasticizers; hydrophillic colloids, e.g. gelatin or glue; polyhydric alcohols, e.g. glycol, glycerol or sorbitol; other polymeric bodies, e.g. butadiene polymers and copolymers, cellulose ethers and esters, vinyl ester polymers and copolymers, polyamides, polystyrene, acrylic polymers, vinylidene polymers and copolymers, e.g. vinyl chloride-vinylidene chloride copolymer; phenol-formaldehyde, urea and melamine-aldehyde, alkyd, coumarone, and polyethylene resins; polyvinyl alcohol and acetals; natural resins, e.g. rosin; polymerizable fatty acids and their esters and polymers thereof; rubber hydrochloride and halogenated rubber; stearic acid.  The products may be cured, e.g. by lead or zinc peroxide or chromate, litharge, red lead, quinone, benzoyl, lauryl or hydrogen peroxide, naphthenates, e.g. those of copper, lead, zinc, cobalt and manganese, aldehydes, e.g. para-formaldehyde, air, ozone, nitrogen peroxide, halogens, or hypohalites.  The uncured products are soluble in benzene, xylene and chlorinated hydrocarbons, but the cured products are insoluble.  The products may be used for coating; impregnating, e.g. textiles, paper, felt, sheet asbestos; manufacture of laminated structures, flexible adhesives, putties and filleting materials, can-sealing materials, and tank linings; casting, e.g. to make printers rollers; and moulding.  In examples: (1), (2) a polymer obtained by reaction of sodium tetrasulphide with a mixture comprising 49 parts of dichlordiethyl formal to 1 part 1 : 2 : 3-trichlorpropane and pre-treated with caustic soda solution to remove labile sulphur is treated with sodium hydrosulphide and sodium sulphite to obtain (1) a coagulable latex, or (2) a liquid product; (3) the product of example (1) is cured by heating in a p  mould with zinc oxide and chromate, paraformaldehyde, carbon black and stearic acid; (4) the product of example (2) is cured cold by admixture with lead peroxide; (5) the product of example (2) is cured by heating with zinc peroxide; (6) a stable mixture of fully dried product and zinc chromate is cured when desired by adding the slightly moist product of example (2), with or without heating; (7) fabric, paper, felt or sheet asbestos is impregnated during or after manufacture with one of the above curing agents and then with the liquid product; or (8) the fibrous material is first impregnated with the product and then treated with the curing agent.  The Specification as open to inspection under Sect. 91 refers to the following additional halogen compounds for the preparation of the starting polymers: tri - (chloromethoxy) - benzene, trichlorobenzene, b  : b 1-dichlorethylether, chlorethoxychlorethyl ether, chlorinated paraffin of the empirical formula C24H44Cl6, and b  : b 1 : g  : g 1-tetrachlor-n-propyl ether.  It als refers to treatment of the starting polymers with reducing agents in general and additionally specifies nascent hydrogen prepared by the action of metals with water, acids or alkalis, e.g. zinc or aluminium with caustic alkalis or magnesium or calcium with water, in which case no oxygen acceptor need be present.  As curing agents there are mentioned oxidizing agents, e.g. peroxides, per-salts, polysulphides, chromates, manganates and permanganates in general; formaldehyde, acetaldehyde, furfuraldehyde; ketones.  Additional fillers specified are leather and sawdust and additional uses fo the products are floor coverings, rubbery sponges and shock-absorbent materials.  Additional examples are given, and U.S.A.  Specifications 2,049,974, 2,100,351, 2,142,144, 2,142,145, 2,195,380, 2,206,641, 2,206,642, 2,206,643, 2,216,044, 2,221,650, 2,235,621, 2,255,228, 2,278,127 and 2,278,128 are referred to.  This subject-matter does not appear in the Specification as accepted.